Using gas, such as nitrogen, to dispense carbonated beverages is commonly known. However, using nitrogen or other gases to infuse non-carbonated beverages such as coffee, tea, or juice is not commonly known. Infusing juice, or a chilled tea or coffee beverage with nitrogen can enhance the flavor and appearance of the beverage. According to an aspect of the present disclosure, there is provided a system that infuses a gas such as nitrogen into a beverage, such as tea, coffee, or juice.
There are a number of prior art devices that infuse a gas into a liquid. A first method uses a membrane. In the membrane, small passages with very high surface area allow gas to permeate into a liquid. This is similar to human lungs allowing gas into the bloodstream. Issues that need to be considered with this method are the saturation of the gas passages and the physical size of the module. Often, the balance of pressures & thermal variation causes an inconsistent pour.
A second method uses a porous tube. In the porous tube, pressurized gas in a chamber outside of a liquid tube is forced into the liquid within a shower of small bubbles. Issues that need to be considered with this method are the saturation of the gas passages, and the balance of pressures and thermal variation, which tend to cause an inconsistent pour. Further, while this method might work to infuse water like the Bag in Box Barista, other products such as, for example, Post-Mix Coffee, have solids in it and trying to clean it can be problematic. Since this method does not infuse the liquid enough, subsequent restriction with a tortuous path to break up the larger bubbles is required. The resulting beverage may not have the cascading effect for as long as the membrane requires.
Another prior method provides the infusion of a gas such as nitrogen where pressurized nitrogen is controlled via a pilot valve, i.e., an air-operated valve. An intermittent nitrogen pulse is injected into a liquid stream, for example, a coffee stream, within a fitting. The pulse is controlled by the exhaust of the coffee pump. The pump exhaust gas intermittently triggers the pilot valve and is then vented to the atmosphere. Issues to be considered with this approach are, for example: it is sensitive to thermal variation, which may cause an inconsistent pour; the physical size of the module; nitrogen to operate the pump is vented to atmosphere, while in all other methods, 100% of the nitrogen goes into the beverage; and this approach uses a large volume of nitrogen, therefore a larger nitrogen generator or gas bottle is required. This approach is also complex, i.e., there are moving parts that may sometimes fail, and many connections tend to leak.
In another prior art method, gas infusion incorporates the Venturi principle. In the Venturi method, a liquid passes through a choke or throat causing a pressure drop (Venturi vacuum). Gas or another liquid is drawn into the fast moving/negative pressure jet of the liquid at the choke. Then, in the turbulent expansion area downstream of the choke, further mixing of gas and liquid occurs. However, one issue to consider with this method is proper cleaning of the system through which a potable beverage will be dispensed. In a Venturi device, the expansion area where the gas and liquid homogenize must be cleaned periodically to prevent the growth of mold, mildew, and bacteria. This is typically done by running a cleaning solution through the system. But the flow of solution through a Venturi may not properly clean every internal surface and corner.
Thus, there is a need for an improved fluid and gas mixing system for potable beverages that sufficiently aerates a beverage and meets industry sanitization requirements.